Herson, who said that her company analyses "about a billion messages a day," explained that the GlobalView Mail Reputation Service looks for IP addresses where particularly large amounts of mail have been sent out and identifies whether or not they're being used to send out spam. If a certain IP address is identified as the home of a spamming computer, then the system uses a technique known as throttling that places a cap on how many messages can be received by that address within the system. This way, someone who is unwittingly using a zombie computer for legitimate purposes may send out a limited number of messages and not be blocked by the system.

Spam has emerged as the single most draining factor on networks worldwide. And more so because in the increasingly networked world, botnets are so much more networked. The technology being deployed by Commtouch performs real-time monitoring of IP addresses from which mail are received.